The Advanced Imaging for Glaucoma Study (AIGS), a prospective longitudinal multicenter observational study was designed to test the ability of advanced imaging technologies: scanning laser polarimetry (SLP), scanning laser tomography (SLT), time domain optical coherence tomography (TD-OCT), Fourier domain optical coherence tomography (FD-OCT), and Doppler Fourier domain optical coherence tomography measurement of retinal blood flow (Doppler OCT) to improve the early detection of glaucoma and to predict the development of glaucomatous visual field defects. The University of Miami Miller School of Medicine/Bascom Palmer Eye Institute (BPEI), University of Pittsburgh Medical Center (UPMC), and the University of Southern California/Doheny Eye Institute (USC) are Clinical Centers. The Coordinating Center and Chairman's Office are located at Oregon Health and Science University (OHSU). Dr. David Huang, Project Chairman, asked Dr. Richard Parrish, former director of the Ocular Hypertension Treatment Study and Collaborative Initial Glaucoma Treatment Study Optic Disc Reading Centers to establish an Advanced Imaging for Glaucoma-Optic Disc Reading Center (AIGS-ODRC). The rationale was based on the results of non-uniform and unmasked optic disc assessments that were performed by clinical ophthalmologists at the three clinical centers. We propose to achieve five specific aims from assessment of existing AIGS stereoscopic photographs: provide uniform masked side by side readings of optic disc characteristics and determine optic disc conversion and progression endpoints~ compare the clinical centers' determination of optic disc conversion and progression with that of the ODRC~ compare advanced imaging modalities to optic disc determinations~ compare advanced imaging modalities to visual field combined with optic disc determinations~ create a digital database of optic disc photographs available to researchers. The results from the AIGS-ODRC stereoscopic optic disc assessment, a gold standard, low- cost, qualitative technique will be compared with the results obtained with the more expensive and quantitative advanced imaging technologies.